Expression of PirB protein in intact and injured optic nerve and retina of mice.

The aim of this study was to investigate the expression of PirB protein in intact mice ON (optic nerve) and retina, and to evaluate its change after ON injury. The mouse ON crush model was established. The immunohistochemistry and western blot were used to detect PirB expression. We discovered PirB signals were located as beaded arrangement along the ON long axis in intact ON, disordered in injured ON, and distributed mainly in ganglion cell layer in intact and injured retina. Both PirB expression in injured ON and retina were significantly increased at 1-day post injury (1-dpi), nearly peaked at 7-dpi, but thereafter there was no significant change of them till at least 28-dpi. We concluded the expression of PirB was positive in intact ON and retina, and significantly increased after ON injury. These findings, coupled with previous studies, may imply that PirB is probably a critical molecule in inhibition of axonal regeneration by myelin inhibitors after ON injury.